The Dutchman would be dismissed that summer and the shortlist of potential replacements consisted of two names: Mourinho and Guardiola.
Mourinho was Guardiola's coach at Barcelona [Courtesy]

"Slowly but steadily we were going in the wrong direction," recalls Eidur Gudjohnsen. "The second season I was here - Frank Rijkaard was still in charge - is, I think, one of the worst seasons in the recent history of Barcelona where we finished third.

"It wasn't good enough for the standard people set here, not good enough for the club and not good enough for the players we had. Something had to change."

Both men were available as Mourinho had left Chelsea the previous year while Guardiola was in charge of Barcelona B.

"He [Mourinho] is a winner and it felt like a safer choice because he was a big brand, was recently coach at Chelsea and he was on the market," says former vice president Marc Ingla.

A meeting was arranged and Mourinho delivered a PowerPoint presentation to show how he would implement his favoured 4-3-3 formation.

The Portuguese was no stranger to Barcelona having been a key part of Bobby Robson's backroom staff during the Englishman's reign as manager.

It was there he coached, among others, a young Guardiola.

"Mourinho helped us a lot when we were young players; [Louis] Van Gaal often sent him to take Barca B training," says former club captain Xavi in Take the Ball, Pass the Ball, a new documentary about Guardiola's Barcelona reign.

"The rondo, possession, holding on to the ball, positional play; we worked on all of that with Mourinho.

"But when he went to Chelsea, Mourinho's philosophy of the game changed. It's a very different style to the football we play at Barca."

Xavi’s feelings were shared by some of the club's hierarchy but several directors remained intent on appointing Mourinho.

"It was a long process because there were board members who wanted Jose," says former president Joan Laporta. "They argued that we needed a manager who would get results quickly."

Ultimately, however, it was the opinion of club legend Johan Cruyff which swung the decision in Guardiola's favour.

"We wanted to stay faithful to Cruyff’s philosophy," adds Laporta.

"I asked [the directors] if Pep was ready and both Txiki Begiristain and Johan, who saw him regularly, said he was.
The two have gone on to become rivals in different leagues [Courtesy]

"Mourinho's agent [Jorge Mendes] called me and asked, 'Are you going to appoint Mourinho because if you are interested we need to talk,' and I said to him, 'No, Jorge, we’ve chosen Pep Guardiola'."

Two years after Rijkaard had led Barcelona to victory in the Champions League final against Arsenal, he was sacked.

"I told Pep I wanted him to be the next manager," says Laporta. "We were having lunch and he said to me, half joking, “If you appoint me as coach I'll win everything for you'. He honestly said that!"

Guardiola was true to his word, winning the treble in his first season in charge before adding a further 11 trophies to Barcelona's burgeoning cabinet over the next three years.

Mourinho, meanwhile, took charge of Inter Milan that same summer, setting in motion a rivalry that still fizzes more than a decade later.